• 한국초지조사료학회지
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• 제5권2호
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• pp.127-135
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• 1985

옥수수 및 sorghum 식물(植物)에 있어서 생육시기(生育時期)와 환경온도(環境溫度)가 cell-wall constituents의 합성(合成) 및 축적형태(蓄積形態)에 미치는 영향(影響)을 구명(究明)하기 위하여 옥수수의 Blizzard와 sorghum의 Sioux 및 Pioneer 931 품종(品種)을 공시재료(供試材料)로 하여 포장(圃場) 및 Phytotron 시험(試驗)을 실시(實施)하였다. Phytotron의 주(晝)/야간(夜間) 실내온도(室內溫度)는 30/25, 25/20, 28/18 및 $18/8^{\circ}C$로 하였으며 일조(日照)는 30,000-35,000Lux로 13시간(時間) 조사(照謝)하였다. 1979-81년간(年間) 얻어진 결과(結果)를 요약(要約)하면 다음과 같다. 1. 옥수수 및 sorghum의 cell wall constituents는 유수형성기(幼穗形成期)에서 지엽(止葉)이 출현(出現)되는 시기(時期)에 최대(最大)의 합성능력(合成能力)을 갖는다. Neutral Detergence Fiber 및 Acid Detergence Fiber 농도(濃度)는 동화엽면적(同化葉面積)이 최대(最大)인 출수기전후(出穗期前后)에 각각(各各) NDF 52-55% (옥수수) 및 64-68%(Sorghum)와 ADF 30%(옥수수) 및 45% (Sorghum)로 가장 높은 수준(水準)을 나타낸다. 2 Cellulose 및 Hemicellulose는 세포구조막(細胞救造膜)을 형성(形成)하고 있는 structural carbohydrates로 Cellulose가 주(主)로 경조직(莖組織)의 cell wall을 구성(構成)하고 있는데 비해 Hemicellulose는 엽(葉)과 곡실부위(穀實部位)의 세포막구성물질(細胞膜構成物質)로서 중요(重要)한 역할(役割)을 한다. 3. Cell wall constituents의 합성(合成)은 환경온도(環境溫度)가 상승(上昇)됨에 따라 비례적(比例的)으로 증가(增加)한다. 그러나 fructosan, mono- 및 disaccharose 등 non-structural carbohydrates축적(蓄積)은 $30/25^{\circ}C$이상(以上)의 고온(高溫)에서 감소(減少)된다. 고온(高溫)에서의 세포구조막물질(細胞構造膜物質) 증가(增加)는 cell wall을 구성(構成)하고 있는 물질중(物質中) 特(特)히 Cellulose가 급증(急增)된데 기인(其因)된 것으로 온도상승(溫度上昇)에 따른 Cellulose의 합성능력(合成能力)은 Hemicellulose 및 Lignin에 비해 현저(顯著)한 증가(增加)를 보인다. 4 세포구조막물질(細胞構造膜物質)의 증가(增加)는 소화율(消化率) 및 net energy 축적(蓄積)을 크게 저해(沮害)한다. cell wall constituents 중(中) phenol 성분(成分)의 Lignin과 in vitro 소화율간(消化率間)에는 높은 부(負)의 상관(相關)이 있다($P{\leqq}0.1%$). Cellulose 및 Hemicellulose는 sorghum식물(植物)의 경우 소화율(消化率)과 NEL 축적(蓄積)을 크게 악화(惡化)시키나($P{\leqq}0.1%$) 옥수수에 있어서는 이같은 부(負)의 상관관계(相關關係)가 sorghum에서와 같이 크게 나타나지 않는다.

• 한국미생물·생명공학회지
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• 제22권3호
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• pp.233-239
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• 1994

The characteristics of the bacteriophage resistant Lactococcus lactis subsp. cremoris ATCC 11602-A1, the phage-resistant mutant of Lactococcus lactis subsp. cremoris ATCC 11602, was examined. Electron microscopic study of phage adsorption to A1 revealed that after 10 min. incubation of the host-phage mixture, A1 did not show phage adsorption, and after 60 min. did not show a real burst and the release of new phage particles which could be detected in the mixture of its parent strain and phage. However, the phage adsorption rate of A1 after SDS treatment increased to 98%. Moreover, when the cell walls from A1 and parent strain, and the polysaccharide(PS) and peptidoglycan(PG) of their cell wall were mixed with phage and incubated for 15 min., PS and PG from A1 did not bind phage, but only SD-treated cell wall bound phage, and the cell wall and PS of parent strain bound phage. Both A1 and parent strain treated with 0.2 N HCl-and 5% TCA(100$$C) did not bind phage. The results suggest that the phage receptor is still present in the cell wall of the A1, but a cell wall constituent hydrolyzed by SDS blocks phage adsorption by masking the phage receptor. It also suggests that the phage receptor of parent strain is associated with PS of the cell wall.

• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1760-1768
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• 2018

The type strain Bacillus subtilis subsp. subtilis KCTC $3135^T$ was deeply sequenced and annotated, replacing a previous draft genome in this study. The tar and tag genes were involved in synthesizing wall teichoic acids (WTAs), and these genes and their products were previously regarded as the distinguishing difference between B. s. subtilis and B. s. spizizenii. However, a comparative genomic analysis of B. subtilis spp. revealed that both B. s. subtilis and B. s. spizizenii had various types of cell walls. These tar and tag operons were mutually exclusive and the tar genes from B. s. spizizenii were very similar to the genes from non-Bacillus bacteria, unlike the tag genes from B. s. subtilis. The results and previous studies suggest that the tar genes and the tag genes are not inherited after subspecies speciation. The phylogenetic tree based on whole genome sequences showed that each subspecies clearly formed a monophyletic group, while the tree based on tar genes showed that monophyletic groups were formed according to the cell wall type rather than the subspecies. These findings indicate that the tar genes and the presence of ribitol as a cell-wall constituent were not the distinguishing difference between the subspecies of B. subtilis and that the description of subspecies B. s. spizizenii should be updated.

• 한국분말재료학회지
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• 제27권2호
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• pp.119-125
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• 2020

One of the promising candidates for accident-tolerant fuel (ATF), a ceramic microcell fuel, which can be distinguished by an unusual cell-like microstructure (UO₂ grain cell surrounded by a doped oxide cell wall), is being developed. This study deals with the microstructural observation of the constituent phases and the wetting behaviors of the cell wall materials in three kinds of ceramic microcell UO₂ pellets: Si-Ti-O (STO), Si-Cr-O (SCO), and Al-Si-Ti-O (ASTO). The chemical and physical states of the cell wall materials are estimated by HSC Chemistry and confirmed by experiment to be mixtures of Si-O and Ti-O for the STO; Si-O and Cr-O for SCO; and Si-O, Ti-O, and Al-Si-O for the ASTO. From their morphology at triple junctions, UO₂ grains appear to be wet by the Si-O or Al-Si-O rather than other oxides, providing a benefit on the capture-ability of the ceramic microcell cell wall. The wetting behavior can be explained by the relationships between the interface energy and the contact angle.

• 한국작물학회지
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• 제43권1호
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• pp.32-37
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• 1998

The objective of this study was to analyze lodging-related traits using different cultivars from Korea, Japan, and the U.S. in direct seeded rice on dry paddy field. Stem diameter and culm wall thickness were highest in 'Caloro' followed by 'Nongan', 'M202', and 'Calrose'. All the U.S. cultivars were higher than the others in stem diameter and culm wall thickness. These two traits were important with regard to lodging. The highest breaking strength (1442g) was observed in Caloro. 'Gancheoek', 'Dongjin', and transplanted 'Hatsuboshi' showed more than 1000g in breaking strength. Lodging index was lowest in Hatsuboshi followed by Nongan and Gancheok. Even though breaking strength of the U.S. cultivars was higher than others, their lodging index values were high. There were no statistically significant differences in starch content. However, Calrose, Caloro, Dongjin, and Koshihikari were relatively higher than others in starch content. Positive correlations were found between culm base weight, lignin and breaking strength. High contents of lignin and cellulose were observed in Nongan, transplanted Hatsuboshi, Calrose, and Caloro. Traits such as stem diameter, culm wall thickness, bending moment, culm length, breaking strength, cellulose, lignin, and culm base weight were closely related to a lodging index. According to path coefficient analysis, most important traits were culm length, stem diameter, thickness of clum wall, and top plant weight.

• Asian-Australasian Journal of Animal Sciences
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• 제12권7호
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• pp.1049-1053
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• 1999

Chopped wheat straw (0.5-1.5 cm) was subjected to different treatment combinations in a $5{\times}4$ factorial arrangement involving the five levels of urea (0, 2, 3, 4 and 5%, w/w) and four levels of lime (0, 2, 4 and 6%, w/w) at 50% moisture and kept for 3 wk reaction period at about $35{^{\circ}C}$ in laboratory. Treated wheat straw samples were analyzed to study the associative effect of urea and lime on chemical composition, in sacco and in vitro digestibilities. Results showed that cell wall constituents (CWC) solubilized significantly (p<0.01) due to urea and lime treatment on one hand and substantially increase the crude protein (CP) on the other in wheat straw. The main effect on synergism of both chemicals was noticed on organic matter (OM), neutral detergent fibre (NDF), hemicellulose (HC), acid detergent lignin (ADL) and silica by solubilising their contents as a result of considerable increase in cell contents in treated wheat straw. The respective decreases were 5.45, 13.0, 37.23, 44.95 and 26.16% in different treatment combinations. The most interesting feature of the treatment was evident by increase in ash content on each level of lime application. CP content increase up to 12.78% due to urea treatment in comparison with untreated wheat straw (2.56%). The effect of solubilization of structural carbohydrates and increased crude protein due to synergistic effect of urea and lime were clearly seen on improved digestibility of OM and DM. The increase in ISOMD, ISDMD, and IVDMD were 21.67, 21.67, 16.24, and 17.5 units. The increase in digestibility were relative to additions of both chemicals and digestibility values increased with increasing levels of urea plus lime concentration in different treatment combination. The maximum improvement was noticed at 4% urea and 4% lime levels at 50% moisture for 3 wk reaction period in treated wheat straw.

• 한국버섯학회지
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• 제14권4호
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• pp.127-135
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• 2016

Cellulose is the most abundant organic polymer constituent of the cell wall of green plants and of various forms of algae. The complexity of lignocellulosic biomass is a major challenge in industrial research. Most mushroom species that naturally grow on soil or wood possess cellulases and the corresponding enzymatic system and, potential candidates for the direct bioconversion of softwood polysaccharides into fermentable sugars. However, there have been fewer studies on mushroom cellulases than on fungi such as Trichoderma spp., exploit the full potential of mushroom cellulases. This review will focus on the current status ofmushroom cellulase research and applications and will provide insight into promising future prospects.

• 한국미생물·생명공학회지
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• 제27권5호
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• pp.378-384
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• 1999

Protopectinase (PPases) are heterologous group of enzymes that degrade pectin from the insoluble protopection which is constituent of the middle lamella and primary cell wall of higher plants by restricted depolymerization. From the previous report[6], enzymatically separated plant cells, which are produced from plant tissues by PPases treatment, showed well-conserved cellular components with their rigid cell wall and this characteristic is applicable to preparation of novel food material. The purpose of this study is to investigate the effect of medium composition of PPase production from Bacillus subtilis EK11 which was selected as a PPase producer. Various carbon sources and concentrations on PPase production were studied and corn starch at 0.7% was the most effective for production of PPase. Among the nitrogen sources, yeast extract was the most effective for PPase production and the effect of (NH4)2SO4 was notable as inotganic nitrogen source. Inorganic compounds such as KH2PO4, K2HPO4, Na3-citrate.2H2O and MgSO4 were optimized for PPase production. PPase activity was inhibited by the adition of Ba2+ or Zn2+. The optimal medium for PPase production was devised: 0.7% corn starch, 0.3% yeast extract, 1.4% KH2PO4, 0.6% K2HPO4, 0.1% Na3-citrate.2H2O and 0.02% MgSO4. PPase production by using the optimum medium was carried out with shaking cultivation at 37$^{\circ}C$. The maximum PPase activity of 256unit/ml could be obtained after the cultivation for 48hrs. The activity was increased about 2.2timesthan the activity, 112 unit/ml, in basal medium.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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• pp.1310-1317
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• 2018

The stems of Dendrobium moniliforme have been used in traditional herbal medicine for the treatment of fever and lack of body fluid in Korea. In this study, we investigated anti-inflammatory effects of the aqueous extract of D. moniliforme stems (DM) in response to lipoteichoic acid (LTA), a major constituent of the cell wall of Gram-positive bacteria. DM inhibited LTA-induced expression of a pro-inflammatory mediator inducible nitric oxide synthase (iNOS) in the murine macrophages. And DM induced expression of heme oxygenase-1 (HO-1) at the transcriptional level. Conversely, the knockdown of HO-1 expression by siRNA markedly reversed the inhibitory effects of DM on LTA-induced iNOS expression. We also demonstrated that nuclear translocation of Nrf2 was increased following treatment with DM. In addition, DM-mediated Nrf2 activation and HO-1 expression were suppressed by PI3K/Akt and p38 inhibitors; treatment with DM also resulted in phosphorylation of Akt and p38. These results suggest that DM inhibits the expression of iNOS in LTA-stimulated macrophages, and that these effects are mediated by the upregulation of HO-1 expression via PI3K/Akt/p38-Nrf2 signaling.

• Journal of Microbiology
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• 제45권5호
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• pp.460-465
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• 2007

This study was carried out in order to investigate the potential of using plant oils derived from Leptospermum petersonii Bailey and Syzygium aromaticum L. Merr. Et Perry as natural antifungal agents. The antifungal effects of essential oils at concentrations of 0.05, 0.1, 0.15, and 0.2 mg/ml on the dermatophytes Microsporum canis (KCTC 6591), Trichophyton mentagrophytes (KCTC 6077), Trichophyton rubrum (KCCM 60443), Epidermophyton floccosum (KCCM 11667), and Microsporum gypseum were evaluated using the agar diffusion method. The major constituents of the active fraction against the dermatophytes were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography analysis. The antifungal activities of S. aromaticum oil (clove oil) against the dermatophytes tested were highest at a concentration of 0.2mg/ml, with an effectiveness of more than 60%. Hyphal growth was completely inhibited in T. mentagrophytes, T. rubrum, and M. gypseum by treatment with clove oil at a concentration of 0.2 mg/ml. Eugenol was the most effective antifungal constituent of clove oil against the dermatophytes T. mentagrophytes and M. canis. Morphological changes in the hyphae of T. mentagrophytes, such as damage to the cell wall and cell membrane and the expansion of the endoplasmic reticulum, after treatment with 0.11 mg/ml eugenol were observed by transmission electron microscopy (TEM). At a concentration of 0.2 mg/ml, L. petersonii oil (LPO) was more than 90% effective against all of the dermatophytes tested, with the exception of T. rubrum. Geranial was determined to be the most active antifungal constituent of L. petersonii oil. Taken together, the results of this study demonstrate that clove and tea tree oils exhibited significant antifungal activities against the dermatophytes tested in this study.